Lymphocytes are the most general type of white blood cells that help the body identify and destroy antigens and cancer cells. They are divided into B and T cells. The B lymphocytes produce antibodies that recognize foreign substances or antigen and attach themselves to them. They are programmed individually to make one specific antibody. When these B cells come across its triggering antigens it gives rise to larger cells known as plasma cells. On the other hand, T lymphocytes are cells that are programmed to recognize, to respond and to remember antigens. They contribute to the immune system defenses in two main ways. Some of them direct and regulate the immune responses. Thus, when they are being stimulated by the antigenic material presented by the macrophages, the T cells make a chemical message known as lymphokines that signals other cells. The other T lymphocytes destroy targeted cells on direct contact.
